Failed construction RegionServer 解决方案

今天装hbase 伪分布式的时候，出现了一个错误

2019-03-19 21:21:22,920 ERROR [main] regionserver.HRegionServer: Failed construction RegionServer
java.lang.NoClassDefFoundError: org/apache/htrace/SamplerBuilder
	at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:644)
	at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:628)
	at org.apache.hadoop.hdfs.DistributedFileSystem.initialize(DistributedFileSystem.java:149)
	at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2667)
	at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:93)
	at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2701)
	at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2683)
	at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:372)
	at org.apache.hadoop.fs.Path.getFileSystem(Path.java:295)
	at org.apache.hadoop.hbase.util.CommonFSUtils.getRootDir(CommonFSUtils.java:362)
	at org.apache.hadoop.hbase.util.CommonFSUtils.isValidWALRootDir(CommonFSUtils.java:411)
	at org.apache.hadoop.hbase.util.CommonFSUtils.getWALRootDir(CommonFSUtils.java:387)
	at org.apache.hadoop.hbase.regionserver.HRegionServer.initializeFileSystem(HRegionServer.java:704)
	at org.apache.hadoop.hbase.regionserver.HRegionServer.<init>(HRegionServer.java:613)
	at org.apache.hadoop.hbase.master.HMaster.<init>(HMaster.java:489)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at org.apache.hadoop.hbase.master.HMaster.constructMaster(HMaster.java:3093)
	at org.apache.hadoop.hbase.master.HMasterCommandLine.startMaster(HMasterCommandLine.java:236)
	at org.apache.hadoop.hbase.master.HMasterCommandLine.run(HMasterCommandLine.java:140)
	at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
	at org.apache.hadoop.hbase.util.ServerCommandLine.doMain(ServerCommandLine.java:149)
	at org.apache.hadoop.hbase.master.HMaster.main(HMaster.java:3111)
Caused by: java.lang.ClassNotFoundException: org.apache.htrace.SamplerBuilder
	at java.URLClassLoader.findClass(URLClassLoader.java:382)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 25 more
2019-03-19 21:21:22,921 ERROR [main] master.HMasterCommandLine: Master exiting
java.lang.RuntimeException: Failed construction of Master: class org.apache.hadoop.hbase.master.HMaster. 
	at org.apache.hadoop.hbase.master.HMaster.constructMaster(HMaster.java:3100)
	at org.apache.hadoop.hbase.master.HMasterCommandLine.startMaster(HMasterCommandLine.java:236)
	at org.apache.hadoop.hbase.master.HMasterCommandLine.run(HMasterCommandLine.java:140)
	at org.apache.hadoop.util.ToolRunner.run(ToolRunner.java:70)
	at org.apache.hadoop.hbase.util.ServerCommandLine.doMain(ServerCommandLine.java:149)
	at org.apache.hadoop.hbase.master.HMaster.main(HMaster.java:3111)
Caused by: java.lang.NoClassDefFoundError: org/apache/htrace/SamplerBuilder
	at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:644)
	at org.apache.hadoop.hdfs.DFSClient.<init>(DFSClient.java:628)
	at org.apache.hadoop.hdfs.DistributedFileSystem.initialize(DistributedFileSystem.java:149)
	at org.apache.hadoop.fs.FileSystem.createFileSystem(FileSystem.java:2667)
	at org.apache.hadoop.fs.FileSystem.access$200(FileSystem.java:93)
	at org.apache.hadoop.fs.FileSystem$Cache.getInternal(FileSystem.java:2701)
	at org.apache.hadoop.fs.FileSystem$Cache.get(FileSystem.java:2683)
	at org.apache.hadoop.fs.FileSystem.get(FileSystem.java:372)
	at org.apache.hadoop.fs.Path.getFileSystem(Path.java:295)
	at org.apache.hadoop.hbase.util.CommonFSUtils.getRootDir(CommonFSUtils.java:362)
	at org.apache.hadoop.hbase.util.CommonFSUtils.isValidWALRootDir(CommonFSUtils.java:411)
	at org.apache.hadoop.hbase.util.CommonFSUtils.getWALRootDir(CommonFSUtils.java:387)
	at org.apache.hadoop.hbase.regionserver.HRegionServer.initializeFileSystem(HRegionServer.java:704)
	at org.apache.hadoop.hbase.regionserver.HRegionServer.<init>(HRegionServer.java:613)
	at org.apache.hadoop.hbase.master.HMaster.<init>(HMaster.java:489)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
	at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
	at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
	at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
	at org.apache.hadoop.hbase.master.HMaster.constructMaster(HMaster.java:3093)
	... 5 more
Caused by: java.lang.ClassNotFoundException: org.apache.htrace.SamplerBuilder
	at java.URLClassLoader.findClass(URLClassLoader.java:382)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
	... 25 more

解决方案：

把/hbase-2.1.2/lib/client-facing-thirdparty目录下的htrace-core-3.1.0-incubating.jar 复制到/hbase-2.1.2/lib即可。

我觉得是hbase寻找这个类的时候直接在 /hbase-2.1.2/lib 下寻找，发现找不到，所以调用这个构造函数的时候无法生成RegionServer对象。就抛出了异常。所以就把htrace-core-3.1.0-incubating.jar 这个包放到/hbase-2.1.2/lib这里就可以解决了。只是个人猜想。